The xuv spectra of free metal atoms obtained by absorption, photoion, photoelectron ana two-photon spectroscopy are reviewed. iine experimentai resuirs are discussed in comparison with the predictions of the different theorstical approaches. Emphasis is put on the basic excitation and de-excitation processes, the importance of electron correlation, on common features of groups and on trends along series.

The absorption spectra of atomic W and Pt have been recorded by the dual laser plasma technique in the range of the 4f and Sp excitations. Broad, strong and asymmetric Sp+ 5d resonances dominate the spectra. The h 4f+Sd transitions give rise to prominent maxima superimposed on the high energy slope ofthe 5p-5d resonances. Strong coupling to the Sd+ sf continuum manifests itself in the asymmetric profiles of the resonances and the extremely low cross section below the 5p onset for atomic W. The experimental results are compared to spectra calculated within the many-body perturbation theory and the relativistic random-phase approximation.

Using monochromatized extreme-UV radiation from the undulator beamline BW3 at HASYLAB we have measured at high resolution (E/ Delta E approximately 7000) the Li+ photoion yield spectrum at excitation energies corresponding to transitions to double K-shell vacancy states. A number of such resonances including single-photon-three-electron excitations, e.g. 1s22s(2S) to 2p3(2p), have been observed for the first time. The spectrum is tentatively classified with the aid of Hartree-Fock calculations.

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